Facile preparation of silicon/carbon anode derived from macroporous methylsilsesquioxane for lithium-ion batteries

Silicon/carbon (Si/C) anode materials were fabricated by an improved magnesiothermic reduction of macroporous methylsilsesquioxane (MSQ) as the precursor, followed by a carbon filling. The macroporous MSQ is reduced to macroporous silicon, and the pitch and graphite are filled into the pore structure of silicon via the impregnation and carbonization to prepare Si/C anode materials. The obtained Si/C anodes exhibit superior comprehensive electrochemical performance with a high initial charge and discharge capacity of 1437.0 and 1180.6 mAh g-1 at a current density of 300 mA g-1 and a remarkable initial coulombic efficiency of 82.16%. This work provides a facile approach for the preparation of anodes for lithium-ion batteries. The silicon fabricated by the improved magnesiothermic reduction retains the macroporous structure of the original MSQ monoliths.The pitch impregnation and carbonization achieves the uniform filling of carbon inside the macropores of silicon.The as-prepared Si/C anodes exhibit excellent comprehensive electrochemical performances.